Abstract: Microwave absorbing material was prepared using epoxy resin as matrix and carbonyl iron powder, phosphate carbonyl iron powder,carbonyl iron powder modified by silane coupling agent,Fe Ni alloyed powder as absorbing agent.The electric volume resistivity,voltage breakdown strength,magnetic loss and absorption loss of the microwave absorber were measured,and the effects of factors on absorption properties under different frequency bands were studied.The results show that absorber made by phosphate carbonyl iron powder and silane modified carbonyl iron powder have the electric volume resistivity above 5.62×10₆Ω·cm,breakdown strength above 700V/mm and absorption loss of 3.7 to 7.0dB/mm in frequency range of 10 to 18GHz.Higher electric volume resistivity makes absorber has nicer high frequency characteristic.The absorber prepared using sheeted alloy powder and phosphate carbonyl iron powder has good ability of magnetic loss and has absorption loss of 0.9 to 4.2dB/mm in frequency range of 2 to 7GHz.